Hydraulic lift with rotation lock for beauty chair



Jan. 10, 1967 P. c. JOHNSON HYDRAULIC LIFT WITH ROTATION LUCK FOR BEAUTY CHAIR Filed Aug. 17, 1 964 ma M 4 M I G v 10 v0 m d m 9 O G l m h e M j w 5 5\\m H n m w H a a 1 2 V n B A %2 4 4 2 M K B 8 1 a a rfl 5 TH 12.4444 m 5 I 4 5 A m 9 m m y T, j w a m aw 6 l 3 K E d R 1 l O 0 4 4 United States Patent M 3,296,935 HYDRAULIC LIFT WITH ROTATIUN LOCK FOR BEAUTY CHAIR Philip C. Johnson, Cincinnati, Ohio, assignor to F & F

Koenigkramer Company, Cincinnati, Ohio, a corporation of Ohio Filed Aug. 17, 1964, Ser. No. 390,168 Claims. (CI. 91-41) This invention relates to hydraulic lifts with rotation locks for use in beauty chairs, medical chairs or the like.

This application is a continuation-in-part of my copending application Ser. No. 814,500 for Hydraulic Lift with Rotation Lock for Beauty Chair, filed May 20, 1959 which matured as United States Patent No. 3,146,592 on Sept. 1, 1964.

An object of this invention is to provide a lift for beauty chairs and the like, adapted to support, raise and lower the seat portion thereof and to permit swinging of the seat into desired orientation and having means for locking the seat in any selected orientation as desired.

Another object of this invention is to provide a device of the foregoing character in which a single lever serves to actuate and control raising and lowering of the lift and locking of a seat supported thereon in fixed orientation as desired.

A further object of this invention is to provide a device of the above character in which said lift and lock means are interconnected to preclude raising or lowering of the seat while the seat is locked in fixed orientation.

A further object of this invention is to provide a device of the above character in which said single lever control is pivoted about an axis in predetermined relation to stationary portions of the chair and does not travel with the movable seat thereof.

Another object of this invention is to provide an hydraulic lift with rotation lock for beauty chairs and the like which is sturdy, reliable and simple in construction as well as easy and simple to operate and which may be made at moderate cost.

Another object of this invention is to provide a lift with rotation lock having a single actuating pedal lever pivoted on a single axis for movement in a predetermined portion of its arc of swing to actuate pumping means of the hydraulic lift to extend or raise the lift and for movement in a predetermined second portion of its arc of swing to effect controlled lowering of the lift by regulating the release of fluid from the lift cylinder and for movement in a predetermined third portion of its arc of swing to actuate a locking device to secure the lift piston rod against rotation relative to the stationary portion of the lift.

A further object of this invention is to provide an hydraulic lift in which the lift piston rod extends through a guide wherein a lock shoe is advanceable thereagainst through a radially oriented bore under forces applied by a crank cam acting through a pressure shoe.

The above and other objects and features of this invention will in part be obvious and will in part be apparent to those having ordinary skill in the art to which this invention pertains.

In the accompanying drawing and the following description of the embodiment disclosed therein, like reference characters indicate like parts.

In the drawing:

FIG. 1 is a view in side elevation partly in section to more clearly show details of construction of an hydraulic lift with rotation lock constructed in accordance with what presently appears to be a preferred embodiment of this invention;

FIG. 2 is a plan view of the hydraulic lift with rota- 3,296,935 Patented Jan. 10, 1967 tion lock show in FIG. 1, portions thereof being broken away for purposes of illustration;

FIG. 3 is a motion diagram of portions of the device of FIGS. 1 and 2; and

FIG. 4 is a fragmentary view, partly in section, taken on the line 4-4 of FIG. 2.

The illustrative embodiment shown in the drawing comprises an hydraulic lift 11, substantial portions of which may be identical or similar in construction to the construction of the lift illustrated in my above mentioned copending application. Therefore, as to any details of construction of the lift not shown or described in this application, reference may be had to the disclosure of my said copending application.

Lift 11 has a bottom 12 which may be mounted on a chair base 13 by means such as bolts 14 extending through integral lug portions 121 of the base 12. An external casing or shell 15 extends upwardly from bottom 12 to top or head 16. Annular seal 17 cooperates with head 16 and casing 15 to render the juncture between the head and casing, fluid and dirt tight. Tie bolts 18 extend downwardly through head 16 and threadedly engage bottom 12 to secure the bottom, casing, and head in assembled relation. Lift actuating pump piston rod 19 extends upwardly through an aperture in head 16 which serves as a supporting guide bearing for rod 19. Head 16 supports seal ring 20 annularly of rod 19. Pump piston rod 19 is longitudinally reciprocable between its uppermost position in which stop means such as pin 21 engages the under side of head 16 as is shown in full lines in FIG. 1, and its lowermost position in which only a portion of rod 19 projects a small distance upwardly from the guide aperture in head 16, a position indicated by dash-dot-dot-dot lines in FIG. 1. The head 16 supports the upper portion of lift cylinder 22 with the cylinder bore in coaxial relation to the guide bore 24- in head 16 for the lift piston rod 23 above cylinder 22. As shown in FIG. 1, a seal ring 25 is supported in head 16 in sealing engagement with the head and piston rod 23.

A chair seat or the like having a frame 26 may be mounted on piston rod 23 as shown in FIG. 1, wherein a frusto-conic aperture 27 is provided in frame 26 and receives the tapered portion 23! of piston rod 23. The head of bolt 28 engages frame 26 while its shank is threadedly engaged with piston rod 23 to secure the frame 26 and rod 23 in fixed relation to each other.

Head 16 'has two perpendicularly intersecting horizontal bores 30 and 31 which, as shown, may be of the same diameter. The axis of bore 30 extends radially from the axis of piston rod 23 and the bore 24 in which rod 23 is received in head 16.

Pedal shaft 32 is journalled for rotational movement in head 16 with cylindrical portions 33 thereof received and supported in bore 31 of head 16 and laterally of the bore 30. The end portions of pedal shaft 32 project from opposite ends of bore 31 and are each diametrically pierced by a respective one of a pair of parallel bores 34 through which respective parallel portions of pedal 35 extend. The portions of pedal 35 received in the bores 34, substantially fill them, as shown in FIGS. 2 and 4. Pedal 35 and shaft 32, thus related, move in unison about the axis of shaft 32. Pedal 35 is preferably secured against movement axially of bores 34, as by advancing set screws 37 axially through the end portions of shaft 32 into recesses 38 provided in pedal 35, as shown in FIG. 4.

If desired, suitable washers 36 may be provided annularly of shaft 32 and between pedal 35 and head 16, as shown in FIGS. 2 and 4, to substantially preclude axial shifting of shaft 35.

A pivot pin or shaft 39 is supported adjacent its ends by pedal 35 adjacent ends 40 thereof. A roller 41 is (3 journalled for rotation on pin shaft 39 between the end portions of pedal 35.

When pedal 35 is swung about the axis of pedal shaft 32, between the neutral position N, shown in full lines in FIG. 1, and the lowermost position L, shown in dashdot-dot-dot lines, roller 41 is in rolling contact with the horizontal flat upper surface of pump piston rod 19.

To elevate piston rod 23 and the structure mounted thereon to a higher position not above the upper limit on such elevation, stirrup portion 35s of pedal 35 may be advanced, one or more times as desired, by foot applied force, from its normal position N, downwardly toward position P, actuating the pump (not shown) to force fluid into the cylinder 22. Pump piston rod 19 is spring biased to the full line position of FIG. 1 corresponding to pedal position N.

Movement of pump piston rod 19 from the position shown in dash-dot-dot lines in FIG. 1, corresponding to pedal position P, toward the fully depressed position shown in dash-dot-dot-dot lines in FIG. 1, corresponding to pedal position L, is also resisted by forces produced by supplemental biasing means such that position P is clearly sensible to an operator through his foot in engagement with stirrup portion 35s.

Movement of pedal 35 from position P toward position L effects corresponding progressive opening of a release valve (not shown) through which fluid may escape from cylinder 22. Piston rod 23 may thus be lowered at a speed cor-responding to the rate of fluid escape from cylinder 22 determined by the extent to which the release valve is opened.

Since beauty chair seats, medical chair seats and the like are preferably rotatable, piston rod 23 is cylindrical and may be rotated on its vertical axis relative to head 16. However, it is also preferable that such seats and the like be lockable in any orientation into which same can be rotated.

The cylindrical surface of piston rod 23 is smooth and carefully finished as by polishing or the like so as to permit good fluid-tight and dust-tight sealing with cooperating seal elements. The surface of piston rod 23 is also in normal operation covered by a film of lubricating oil, grease or the like.

Lock shoe 42 has a substantially cylindrical convex peripheral surface and a diametral cross-section sub stantially the same as that of bore 30 in which lock shoe 42 is slidably received. Shoe 42 has a concave cylindrical surface 43 advanceable against the convex cylindrical surface of piston rod 23. Surface 43 is preferably of a radius substantially equal to that of rod 23 so that the vertical center line of symmetry of the lock shoe surface 43 and portions 54 and 55 tend to make unison contact with the surface of rod 23 as the lock shoe 42 is subjected to greater and greater force tending to advance it toward rod 23 as hereinafter explained. Lock shoe 42, on its side opposite face 43, has a convex-spherical back face 44, the radius through the center point of which substantially coincides with the longitudinal axis of bore 30.

Bore 30 receives and is spanned by the cylindrical central cam portion 45 of pedal shaft 32. The longitudinal axis of cam portion 45 is parallel to, but spaced radially from, the longitudinal axis of the remainder of pedal shaft 32.

Pressure shoe 46 is interposed between cam 45 which engagea-bly cooperates with its mating concave cylindrical surface 47 and lock shoe 42, the convex spherical face 44 of which cooperates with concave spherical face 48 of shoe 46.

Piston rod 23, which may be steel, is supported in the bore 24 of head 16, adjacent lock shoe 42. Lock shoe 42 is preferably a softer material than rod 23, such as aluminum, aluminum alloy, or the like, so as to avoid damage to the smoothly finished surface of rod 23, and one preferably having a comparatively high co-efficient of friction in engagement with the material of rod 23 so as to obtain good locking cooperation. Pressure shoe 46 is preferably a hard, stiff material and suitably lubricated.

Piston rod 23 may be locked against rotation in any position of elevation as desired, by swinging pedal 35 from position N toward position RL in FIG. 1. Such movement disengages roller 41 from pump piston rod 19 precluding raising or lowering of piston rod 23. Also, as shown in diagrammatic view FIG. 3, while pedal shaft portions 33 are rotated on their axis 49, also the axis of bore 31, a particular diameter through the axis 49 and the longitudinal axis 50 of pedal shaft cam portion 45 will occupy positions within limits indicated by diameters identified by reference characters N and RL in FIG. 3. The locus of movement of axis 50 is indicated by the arcuate line in FIG. 3.

As shown by FIG. 3, swinging of pedal 35 between positions N and RL is accompanied by travel of cam 45 between positions 45N and 45RL of FIG. 3. Correlated horizontal movement of cooperating pressure shoe 46 toward and away from rod 23 within limits indicated by lines 52 and vertically within limits indicated by lines 53 in FIG. 3 while its spherical surface 48 cooperates with lock shoe surface 44 is effected by such movement of cam 45 in the range between positions 45N and 45RL. As cam 45 is advanced from position 45N to 45RL, the entire surface 43 of the lock shoe is urged into increasingly intimate contact with the opposed cooperating surface area of piston rod 23 as the force applied is increased by movement of cam 45 from position 45N toward 45RL.

When pedal 32 is swung to operate the lift, that is between positions N and L, cam 45 is retracted and in positions between those designated 45N and 45L (FIG. 3), and lock shoe 42 is not under any force urging it along a radius of and against piston rod 23.

By manipulation of the single pedal 32 under forces easily applied by an operators toe or foot, the seat of a medical chair, beauty chair or the like may be selectively raised, lowered and locked against rotation as desired.

As shown in FIG. 1, a protective and decorative cover 57 may be provided, having an aperture 58 through which lift piston rod 23 extends and a pair of vertical slot-like notches 59 through which portions of pedal 35 extend and in which pedal 35 may swing.

Having thus described what presently appears to be a preferred embodiment of the invention, it will be apparent to those having ordinary skill in the art to which this invention pertains, that various modifications and changes may be made in the illustrative embodiment without departing from the spirit or scope of the appended claims.

Therefore, what is claimed as new, and is desired to be secured by Letters Patent, is:

1. In an hydraulic lift for humans the combination comprising a lift having a body, a cylindrical lift piston rod supported for rotation about its axis and for movement along axis between predetermined limits of extension from said body, a pedal shaft supported for rotation about an axis fixed in relation to said body, a pedal mounted on said shaft and swingable therewith, means for moving said lift piston rod along its axis and actuatable by moving said pedal in a lift range to extend said piston rod from said body and actuatable by moving said pedal in a contiguous lowering range to retract said piston rod, a lock shoe within said body and advanceable parallel to a radius of and into engagement with said lift piston rod, said pedal shaft having means in cooperating relation to said lock shoe and being swingable in a predetermined range of movement to advance said lock shoe into locking engagement with said lift piston rod to lock said rod against rotation relative to said body when said means for moving said lift piston rod are not moved by said pedal, movement of said pedal during locking and unlocking movement of said lock shoe being in a range contiguous to the range of its movement in extending and retracting said lift piston rod.

2. In an hydraulic lift for humans the combination comprising a lift having a body, a smooth cylindrical lift piston rod supported for rotation about its axis and for movement along its axis between predetermined limits of extension through a guide portion of said body, means for moving said lift piston rod along its axis, a pedal shaft supported for rotation about an axis fixed in relation to said body, a pedal mounted on said shaft and swingable therewith to actuate said means for moving said lift piston rod along its axis and swingable in a lift range to extend said piston rod from said body and swingable in a contiguous lowering range to retract said piston rod, a lock shoe movable toward and away from said rod in said guide portion of said body, the lock shoe having a concave cylindrical surface engageable with said cylindrical rod and a convex spherical surface remote from said rod, a stiff pressure shoe having a concave spherical surface in cooperating relation to said spherical surface of said lock shoe, said pedal shaft having a cam portion in cooperating relation to said pressure shoe and being swingable in a predetermined range to advance said pressure and lock shoes toward said lift piston rod and press said lock shoe into locking engagement with said rod to lock said rod against rotation relative to said guide, movement of said pedal during locking and unlocking movement of said lock shoe being in a range contiguous to the range of its movement in extending and retracting said lift piston rod.

3. In an elevatable chair having a base, an hydraulic lift fixedly mounted on said base and having a rotatable piston rod extendable between predetermined upper and lower limits, the combination comprising a guide, a hard smooth cylindrical lift piston rod movable longitudinally and rotatably in said guide, a softer lock shoe movable toward and away from said rod in said guide and having a convex surface remote from said rod and a concave surface adjacent and engageable with said piston rod, a hard stiff pressure shoe in said guide and having a concave surface slightly smaller in area than and in supporting cooperative contact with said convex surface of said lock shoe and cam means actuatable to urge said pressure shoe against said lock shoe to press the lock shoe against said lift piston rod to secure same in fixed relation to said guide while substantially all of the area of each of the opposite surfaces of the softer lock shoe are supported by contact with respective opposed surfaces of said piston rod and pressure shoe.

4. In an elevatable chair having a base, an hydraulic lift fixedly mounted on said base and having a rotatable piston rod extendable between predetermined upper and lower limits, the combination comprising a guide, a hard smooth cylindrical lift piston rod movable longitudinally and rotatably in said guide, a hard stiff pressure shoe, a lock shoe between said rod and said pressure shoe and of softer material than said rod and said pressure shoe and movable toward and away from said rod in said guide, opposite faces of said lock shoe substantially conforming with adjacent opposed faces of said piston rod and pressure shoe, and cam means actuata'ble to advance said pressure shoe toward said rod to urge said lock shoe to press against said lift piston rod to secure same in fixed relation to said guide while substantially all of the area of each of the opposite surfaces of the softer lock shoe are supported by contact with respective opposed surfaces of said piston rod and pressure shoe.

5. In an elevatable chair having a base, an hydraulic lit fixedly mounted on said base and having a rotatable piston rod extendable between predetermined upper and lower limits, the combination comprising a guide, a cylindrical lift piston rod movable longitudinally and rotatably in said guide, a lock shoe movable in said guide toward and away from said rod in said guide, the lock shoe having a concave cylindrical surface engageable with said cylindrical rod and a convex spherical surface remote from said rod, a pressure shoe having a concave spherical surface in supporting cooperating relation to said spherical surface of said lock shoe and cam means actuatable to urge said pressure shoe to press said lock shoe against said lift piston rod to secure same in fixed relation to said guide.

6. In an elevatable chair having a base, an hydraulic lift fixedly mounted on said base and having a rotatable piston rod extendable between predetermined upper and lower limits, the combination comprising a guide, a hard smooth cylindrical lift piston rod movable longitudinally and rotatably in said guide, a lock shoe of softer material than said rod and movable toward and away from said rod in said guide, the lock shoe having a concave cylindrical surface engageable with said cylindrical rod and a convex spherical surface remote from said rod, a pressure shoe having a concave spherical surface in supporting cooperating relation to said spherical surface of said lock shoe and cam means actuatable to urge said pressure shoe to press said lock shoe against said lift piston rod to secure same in fixed relation to said guide.

7. In an elevatable chair having a base, an hydraulic lift fixedly mounted on said base and having a rotatable piston rod extendable between predetermined upper and lower limits, the combination comprising a guide, a cylindrical lift piston rod movable longitudinally in said guide, a lock shoe movable toward and away from said rod in said guide, the lock shoe having a concave cylindrical surface engageable with said cylindrical rod and a convex spherical surface remote from said rod, a stiff pressure shoe having a concave spherical surface in cooperating relation to said spherical surface of said lock shoe and means for urging said pressure shoe to press said lock shoe into locking engagement with said lift piston rod to secure same in fixed relation to said guide.

8. In an elevatable chair having a base, an hydraulic lift fixedly mounted on said base and having a rotatable piston rod extend'able between predetermined upper and lower limits, the combination comprising a guide, a hard smooth cylindrical lift piston rod movable longitudinally in said guide, a lock shoe of softer material than said rod and movable radially toward and away from said rod in said guide, the lock shoe having a concave cylindrical surface engageable with said cylindrical rod and a convex spherical surface remote from said rod, a stiff pressure shoe having a concave spherical surface in cooperating relation to said spherical surface of said lock shoe and means for urging said pressure shoe to press said lock shoe into locking engagement with said lift piston rod to secure same in fixed relation to said guide.

9. In a support for humans, the combination comprising a hydraulic lift having a head having a guide bore, a lift piston rod supported in said guide bore for rotation about the axis of the rod and for movement along its axis between predetermined limits of extension through said head, means for moving said rod along its axis, a lock bore in said head extending radially of and intersecting said guide bore, a lock shoe reciprocable in said lock bore and substantially conforming with the lock bore cross-section transversely of said direction of reciprocation, said lock shoe having a complementary concave cylindrical end face for cooperating contact with the convex cylindrical surface of said rod and a convex spherical end face remote from said rod, a pressure shoe adjacent said lock shoe and having a complementary concave spherical end face cooperatively contactable with the convex spherical end face of said lock shoe and a concave cylindrical surface on its end remote from said spherical face, a pedal shaft extending transversely of said lock bore and pivotally movable about an axis parallel to a diameter of said rod, a cylindrical eccentric cam portion of said shaft cooperatively and complementary engageable with said concave cylindrical surface of said pressure shoe, a pedal mounted on said shaft and swingable therewith in a predetermined range of retracting movement to actuate said means for moving said rod along its axis toward its limit position of minimum extension through said head and swingable in a contiguous predetermined range of extending movement to actuate said means for moving said rod along its axis toward its limit position of maximum extension through said head and swingable in a contiguous third range of movement for moving said pressure shoe to advance said lock shoe into locking relation to said rod to clamp same in fixed relation to said head while said means for moving said rod along its axis is not actuated, whereby said lock shoe straddles said rod in said head guide bore and is self-aligning with said rod and said pressure shoe when urged against said rod to clampingly lock same in fixed relation to said head.

10. In a support for humans, the combination comprising a hydraulic lift having a head, a guide bore in fixed relation to said head, a cylindrical lift piston rod supported in said guide bore for rotation about the axis of the rod and for movement along its axis between predetermined limits of extension through said head, means for moving said rod along its axis, a lock bore extending radially of and intersecting said guide bore, a lock shoe reciprocable in said lock bore and substantially conforming with the lock bore cross-section transversely of said direction of reciprocation, said lock shoe having a complementary concave cylindrical end face for cooperating contact with the convex cylindrical surface of said rod and a convex spherical end face remote from said rod, 'a pressure shoe similar in shape to the lock bore cross-section transversely of said direction of lock shoe reciprocation and smaller so as to be movable transversely and longitudinally in said lock bore and having a.

complementary concave spherical end face cooperatively contactable with the convex spherical end face of said lock shoe and a concave cylindrical surface on its end remote from said spherical face, a pedal shaft extending transversely of said lock bore and pivotally mova-ble about an axis parallel to a diameter of said rod, a cylindrical eccentric cam on said shaft cooperatively and complementarily engageable with said concave cylindrical surface of said pressure shoe, a pedal mounted on said shaft and swingable therewith in a predetermined range of retracting movement to actuate said means for moving said rod along its axis toward its limit position of minimum extension through said head and swingable in a contiguous predetermined range of extending movement to actuate said means for moving said rod along its axis toward its limit position of maximum extension through said head and swingable in a contiguous third range of movement for moving said pressure shoe to advance said lock shoe into locking relation to said rod to clamp same in said guide bore in fixed relation to said head while said means for moving said rod along its axis is not actuated, whereby said lock shoe straddles said rod in said guide bore and is self-aligning with said rod and said pressure shoe when urged against said rod to clampingly lock same.

References Cited by the Examiner UNITED STATES PATENTS 885,843 4/1908 Fischer et al -52 1,265,384 5/1918 Rebmann et al. 9215 X 2,854,061 9/1958 Romito 60-52 X 3,105,575 11/1959 Dewar et al. 1882'18 3,146,592 9/1964 Johnson 60-52 JULIUS E. WEST, Primary Examiner. 

5. IN AN ELEVATABLE CHAIR HAVING A BASE, AN HYDRAULIC LIFT FIXEDLY MOUNTED ON SAID BASE AND HAVING A ROTATABLE PISTON ROD EXTENDABLE BETWEEN PREDETERMINED UPPER AND LOWER LIMITS, THE COMBINATION COMPRISING A GUIDE, A CYLINDRICAL LIFT PISTON ROD MOVABLE LONGITUDINALLY AND ROTATABLY IN SAID GUIDE, A LOCK SHOE MOVABLE IN SAID GUIDE TOWARD AND AWAY FROM SAID ROD IN SAID GUIDE, THE LOCK SHOE HAVING A CONCAVE CYLINDRICAL SURFACE ENGAGEABLE WITH SAID CYLINDRICAL ROD AND A CONVEX SPHERICAL SURFACE REMOTE FROM SAID ROD, A PRESSURE SHOE HAVING A CONCAVE SPHERICAL SURFACE IN SUPPORTING COOPERATING RELATION TO SAID SPHERICAL SURFACE OF SAID LOCK SHOE AND CAM MEANS ACTUATABLE TO URGE SAID PRESSURE SHOE TO PRESS SAID LOCK SHOE AGAINST SAID LIFT PISTON ROD TO SECURE SAME IN FIXED RELATION TO SAID GUIDE. 